8.9:1 is low for n/a and would dog performance
Agreed. Lower compression or Dished pistons/bowl type are for forced induction, mainly turbo compression. Most turbocharged factory engines range from 8-9:1 to accommodate boost.
N/A you would go with what Plain Jane said, 12:1 is the best compression ratio for high rpm range power. So the other the offer is better or look around for a 11:1 ratio which is better than 10:1.
2009 Cobalt LS XFE U74
Mods: K&N Typhoon Intake, Option Cat-Back Exhaust, Cosmo Short shifter, Maxxim Ahead 17X7's, MPx shorty antenna, FE5 Strut/shocks, Tein S Techs, Moog endlinks, Moog spring seaters, ZZP shorty header, LSJ downpipe, LNF front grille